Review the auditing data via Archive web by logging in with the service account
or via SQL Management Studio:
SELECT * FROM [MAMAUDIT].[dbo].[audit_log]
Make a backup of the auditing database.
Start deleting the oldest entries. Do not delete all data at once but gradually increase the date for deletion.
delete FROM [MAMAUDIT].[dbo].[audit_log] where LogDate < '2020-05-01'
Make a backup of the database once cleaned and also the transaction log file should decrease in size